S. A. Kuzhel, “On inverse problem in the Lax-Phillips scattering theory for a class of second-order operator-differential equations”, MFAT, vol. 5, no. 2, pp. 40–43, Jun. 1999, Accessed: Dec. 17, 2025. [Online]. Available: https://zen.imath.kiev.ua/index.php/mfat/article/view/88